Aquatic Biofilms and Plastisphere

Increased dependency on plastics, their use in variable products, and improper disposal methods are leading to heavy accumulation of plastics of variable types and size in the environment. As the majority of the earth surface is occupied by aquatic environments, the fate of plastics reaching aquatic ecosystems should be studied. In particular, microplastics (plastics of size less than 5mm) are a serious concern. Aquatic environments act as final sinks for these plastics. Plastics can act as a substrate to colonize, attach, and establish for organisms including diatoms, cyanobacteria, protozoan, fungi, algae, bacteria, and viruses and can form a microecosystem called a plastisphere. Apart from these organisms plastics can also accumulate pollutants including heavy metals, antibiotic-resistant genes, pathogens, etc., a process is accelerated by the plastisphere biofilm indicating their vector potential. The smaller size of microplastics and the developed surface biomass will lead to ingestion of these plastics by aquatic organisms like fishes thereby enters human food chain. High-throughput sequencing and omics technologies have contributed to better understanding of plastisphere structure, functions, and their role in biodegradation of plastics. This chapter discusses in detail on the plastisphere composition, factors influencing biofilm formation and community shaping on plastic surface. Vector potential of these plastisphere communities and thereby bioaccumulation of heavy metals, toxic chemicals, pathogens, and antibiotic resistome are also addressed.